Manufacturers who ship assembled lighting fixture units for installation in industrial, commercial or residential settings often incur labor intensive assembly costs at the manufacturing and assembly plant, with the attendant result that the completed fixtures can be large and bulky. Packaging and shipping costs for the units can therefore be considered excessive. The manufacturers have therefore typically resorted to shipment separately of the fixture components or partially assembled units for assembly by the installation workers at the job site. However, the assembly, packaging and shipment separately of the housings for the light fixture units remain substantially labor intensive and costly for the manufacturer. There is therefore indicated a need for light fixture housings that can be inexpensively produced and shipped and which can be easily assembled on-site by the installation workers.